Temperature control device, casting die and method for producing a cast component

ABSTRACT

A temperature control device for a casting die and which includes a connection part having an inlet and an outlet for a temperature control medium, and a heat transfer part having a closed outer body and which is configured for insertion into a corresponding opening in the casting die and by way of which a heat exchange is carried out between the temperature control medium and the casting die.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a National Stage Application of PCT International Application No. PCTEP2011/073102 (filed on Dec. 16, 2011), under 35 U.S.C. §371, which claims priority to German Patent Application No. DE 10 2010 063 468.9 (filed on Dec. 17, 2010), which are each hereby incorporated by reference in their respective entireties.

TECHNICAL FIELD

A temperature control device, a casting die and a method for producing a cast component using a temperature control device.

BACKGROUND

The temperature of casting dies, in particular for diecasting light metals, often has to be controlled to set optimal process parameters. Cooling before a cast component is removed from the mold is particularly important. This is important particularly in the case of especially thin-walled cast components, since deformation upon removal from the die is minimized by setting the correct demolding temperature. Similarly, controlling the temperature of the diecasting mold also has an effect on the cycle time and therefore economic importance.

In order to make it possible to dissipate large quantities of heat, casting dies often have a complex system of cooling ducts. However, the position of the cooling ducts here is often restricted by a specific design of the die. In particular, movable elements of the casting die, for example slides, ejectors and the like, limit the possible configuration of the cooling duct system. In addition to such cooling ducts, cooling lances and point cooling systems are also known, with which a cooling medium can be conducted into corresponding bores in the casting die.

A cooling lance of this type is disclosed, for example, in DE 86 186 74 U1. The cooling lance here is inserted into the casting die in such a way that cooling medium is diverted from the usually already present cooling ducts into the lance. The cooling medium emerges from a tube of the cooling lance into the bore in the casting die, and flushes directly around the wall of the casting die which delimits this bore. The cooling medium can flow back by way of an outer duct between the lance and the bore wall.

Cooling lances of this type are also known in a further form which is independent of the normal cooling duct system of the casting die. A cooling lance of this type is disclosed, for example, in JP 2007 144 457 A. Here, too, a tube of the cooling lance protrudes into a receiving bore in the casting die. However, cooling medium is not supplied and carried away again from the normal cooling ducts of the casting die, but rather by way of separate, external hose connections.

Cooling systems of this type have the disadvantage that the cooling medium impinges directly upon the wall of the cast component. This leads to steep temperature gradients in the casting die. Particularly in the case of diecasting dies which experience a high number of temperature cycles on account of low cycle times, these temperature gradients quickly lead to damage. By way of example, what are termed fire cracks thus form in the die surface and, if they occur in the region of a cavity, these are reflected in the cast component produced, such that the material quality thereof is reduced. The thermal loading is in this respect a significant limiting factor for the service life of such a die.

The direct contact between the cooling medium and the die surface additionally entails further risks. If cracks extending as far as into the receiving bore of such a cooling lance or as far as a cooling duct are formed, cooling medium can come into contact with the melt during the casting operation. Especially when aqueous cooling media are used, here there is the risk of vapor explosions, which can destroy dies and are a risk to operating personnel. The cooling lances described are additionally difficult to assemble and have to be sealed off in a complicated manner.

SUMMARY

The present invention is therefore based on the object of providing a temperature control device, a casting die and also a method of the type mentioned in the introduction which make it possible to control the temperature of casting dies in a particularly gentle and reliable manner.

This object is achieved by a temperature control device for a casting die, in particular a diecasting die, having a connection part which has an inlet and an outlet for a temperature control medium, and having a heat transfer part which can be inserted into a corresponding opening in the casting die and by way of which a heat exchange can be carried out between the temperature control medium and the casting die, characterized in that the heat transfer part has a closed outer body.

The object is further achieved by a method for producing a cast component, in particular a diecast component having at least one opening, into which a heat transfer part of a temperature control device, in which the temperature of a casting die is controlled by at least one temperature control device having a connection part which has an inlet and an outlet for a temperature control medium, and having a heat transfer part which can be inserted into a corresponding opening in the casting die and by way of which a heat exchange can be carried out between the temperature control medium and the casting die, characterized in that the heat transfer part has a closed outer body.

A temperature control device in accordance with the invention for a casting die, in particular a diecasting die, comprises a connection part which has an inlet and an outlet for a temperature control medium, and also a heat transfer part which can be inserted into a corresponding opening in the casting die. By way of the heat transfer part, a heat exchange can be carried out between the temperature control medium and the casting die.

In accordance with the invention, it is provided here that the heat transfer part has a closed outer body. In other words, the temperature control medium no longer comes directly into contact with surfaces of the casting die when such a temperature control device is being used. Temperature gradients between the temperature control medium and the cast component are therefore flatter, as a result of which there is a smaller buildup of stress in the casting die. Even in the case of a multiplicity of heating-cooling cycles carried out quickly, significantly fewer residual stress concentrations and thereby also fewer stress cracks or fire cracks therefore form in the casting die than in the case of temperature control devices known from the prior art. The use of the temperature control device in accordance with the invention therefore increases the service life of a corresponding casting die considerably.

The closed design of the outer body of the heat transfer part additionally does away with the need for complicated seals. At the same time, contact between the temperature control medium and the melt used for casting is reliably prevented, and therefore there is no risk of vapor explosions or the like. The temperature control device in accordance with the invention additionally makes it possible to particularly efficiently control the temperature of the casting die, such that if appropriate separate ducts in the casting die for cooling or heating can be dispensed with. This too leads to more stable and more low-stress states in the diecasting molds used.

In a preferred embodiment of the invention, an inner body is arranged within the outer body and, together with the outer body, forms a flow duct, in particular a return flow duct, for the temperature control medium. It is preferable in this respect that flow passes around the inner body over its full extent, such that the flow duct is arranged substantially like a sheath between the two bodies. This makes it possible to provide a particularly large heat transfer surface, and therefore a temperature control device formed in this way makes particularly quick temperature adaptations possible. Similarly, the flow rate can be influenced by a suitable geometric formation of the inner body.

In a further configuration of the invention, a flow duct, in particular an inflow duct, is formed in the inner body. This can be introduced directly into the inner body, for example, in the form of a bore. In the case of a temperature control device configured in this way, the temperature control medium thus flows through the inner body into the heat transfer part, where it passes over from the flow duct of the inner body into the flow duct formed between the inner and outer bodies. This makes it possible to conduct the temperature control medium indirectly into that region of the heat transfer part which dips to the deepest extent into the corresponding opening in the casting die. Before the temperature control medium reaches this region, no significant heat transfer takes place, and therefore the temperature control efficiency at the corresponding locations is particularly good.

In this respect, it is particularly expedient if the inner body extends over a predominant length region of the main body.

In a further configuration of the invention, the inner body additionally comprises a heat storage element. This can be realized, for example, by a receiving space for a medium having a particularly high heat capacity, which is not connected to the flow ducts. Shifts in temperature can be buffered by such a heat store, and therefore the occurrence of sudden changes in temperature which could lead to stress cracks is particularly reliably avoided.

The invention further relates to a casting die, in particular a diecasting die, having at least one opening, into which a heat transfer part of a temperature control device of the type described is inserted. The advantages which arise for the casting die have already been listed here in the description of the temperature control device.

In this case, it is particularly expedient if at least one outer surface region of the main body is in surface contact with a corresponding wall region of the die which delimits the opening. This ensures a conductive transfer of heat between the casting die and the outer body, and therefore the heat can be transferred in a particularly quick and efficient manner. In a preferred embodiment of the invention, the temperature of the casting die can be controlled merely by at least one temperature control device of the type mentioned. In other words, additional cooling or heating ducts or the like are dispensed with in the casting die, such that the casting die is particularly stable and low in stresses.

The opening for receiving the heat transfer part of the temperature control device can in this case be arranged in a mold plate, a slide, a mold frame or the like of the die, the temperature control device described is equally suitable for cooling all die regions.

The invention further relates to a method for producing a cast component, in particular a diecast component, in which the temperature of the casting die is controlled by at least one temperature control device of the type described or which is carried out using a casting die of the type described. A method of this type makes it possible to achieve particularly high service lives of the casting die combined with a high material quality of the cast components produced, since fire cracks or the like arise only to a very small extent.

DRAWINGS

Hereinbelow, the invention and the embodiments thereof will be explained in more detail with reference to the drawing, in which:

FIG. 1 illustrates a longitudinal section through an exemplary embodiment of a temperature control device in accordance with the invention.

FIG. 2 illustrates a side view of the connection part of the temperature control device illustrated in FIG. 1.

FIG. 3 illustrates a side view of the heat transfer part of the temperature control device illustrated in FIG. 1.

FIG. 4 illustrates the temperature control device illustrated in FIG. 1 in an isometric view.

FIG. 5 illustrates a sectional illustration through a further exemplary embodiment of a temperature control device in accordance with the invention.

FIG. 6 illustrates a sectional illustration through a further exemplary embodiment of a temperature control device in accordance with the invention.

FIG. 7 illustrates a side view of the connection part of the temperature control device illustrated in FIG. 6.

FIG. 8 illustrates a sectional illustration through a further exemplary embodiment of a temperature control device in accordance with the invention.

FIG. 9 illustrates a sectional illustration through the temperature control device illustrated in FIG. 8.

FIG. 10 illustrates a further sectional illustration through the temperature control device illustrated in FIG. 8.

FIG. 11 illustrates a longitudinal sectional illustration through a further exemplary embodiment of a temperature control device in accordance with the invention.

FIGS. 12 and 13 illustrate sectional illustrations through the connection part of the temperature control device illustrated in FIG. 11.

FIG. 14 illustrates a longitudinal sectional illustration through a further alternative exemplary embodiment of a temperature control device in accordance with the invention.

FIG. 15 illustrates a cut perspective illustration of an exemplary embodiment of a casting die in accordance with the invention.

DESCRIPTION

A temperature control device denoted as a whole by 10 serves for heating or cooling a diecasting die, in particular for aluminum diecasting or else for diecasting other light metal alloys. The temperature control device 10 has a connection part 12 and also a heat transfer part 14, which can be inserted into a corresponding opening in a diecasting die in order to thus make a transfer of heat possible between the diecasting die and a temperature control medium circulating in the heat transfer part 14. The temperature control medium, for example water, oil or else a gas such as CO2, is supplied by way of a first connection nozzle 16 of the connection part 12, and can flow from there into a flow duct 18 of a tubular inner body of the heat transfer part 14. The choice of the temperature control medium depends in this case on the desired temperature range, which depending on the heating appliance can be, for example, 50° C. to 250° C. The inner body 20 here extends over a significant region of the heat transfer part 14 and is open at its end region 22 which faces toward the heat transfer part 14.

A further sheath-like flow duct 26, by way of which the heat transfer medium can flow back into the connection part 12, is present between the inner body 20 and an outer body 24, which likewise has a tubular form. There, provision is made of a bore 28, which runs substantially perpendicular to the inner body 20, is closed with a locking screw 30 and into which a further bore 32 issues, this further bore finally being connected to a further connection nozzle 34, by way of which the temperature control medium can be carried away and supplied, for example, to a heating or cooling assembly. In the connection part 12, provision is further made of screw openings 36, by way of which the temperature control device 10 can be screwed to the diecasting die.

The outer body 24 of the heat transfer part 14 is in the form of a tube, which is inserted into a bore 38 in a main body 40 of the connection part 12 and is welded thereto by way of a weld seam 42. The end region 44 of the outer body 24 which faces away from the main body 40 is provided with a cover 46, which is likewise connected to the outer body 24 by way of a weld seam 48. If appropriate, the connection can also be made by brazing or other joining methods. The heat transfer part 14 of the temperature control device 10 is thereby completely closed off to the outside, and on insertion of the temperature control device 10 into a diecasting die the temperature control medium does not come into direct contact with the die. This produces particularly flat temperature gradients, and therefore the occurrence of stress cracks or the like in the diecasting die is avoided.

FIG. 3 illustrates the heat transfer part 14 of the temperature control device 10 once again in a view from the outside. The outer body 26 has a first end region 48, by way of which the outer body 26 can be inserted into the main body 40 of the connection part 12. This is adjoined by the actual heat-transferring region 50, which has a cylindrical construction in the example illustrated. As can be seen, the outer body 26 and the cover part 46 are connected by way of a circumferential weld seam 48. A flattened section 52 is furthermore also made in an outer surface of the outer body 26. This makes it possible for the heat transfer region to be inserted into a corresponding bore in a diecasting die. Air displaced by the insertion of the heat transfer part 14 can flow out along the flattened section 52, so that no excess pressure is generated upon insertion of the heat transfer part 14. The thermal expansion of the diecasting die or temperature control device 10 during operation of the diecasting die additionally leads to a press fit between the temperature control device 10 and the diecasting die, such that the heat is conducted purely conductively between the parts. This makes a particularly good transfer of heat possible.

FIG. 4 illustrates the temperature control device 10 once again in a perspective view. The shaping of the temperature control device 10 can be adapted to the respective site of use in the diecasting die. FIG. 5 illustrates, by way of example, a temperature control device 10 which can be inserted in the region of the mold frame and the ejector plate. Here, the connection part 12 consists of elongated tubes, of which a first tube 54 corresponds to the inner body 20 of the heat transfer part 14. The flow duct 18 of the inner body 20 in this case issues into a cavity in the outer body 24, which forms the return flow duct 26. This communicates with a second tube 56, which serves as a connection nozzle for carrying away the cooling medium. Here, too, the outer body 24 is welded to a cover part 46 by way of a weld seam 48. The tubes 54, 56 are held in a base plate 60 of the heat transfer part 14, which is likewise welded to the outer body 24 by way of a circumferential weld seam 62.

Further alternative configurations of a temperature control device are illustrated in the figures which follow. The embodiments illustrated in FIGS. 6 and 8, for each of which a plan view of the end face of the connection part 12 is illustrated in FIGS. 7 and 9, correspond substantially to the embodiment illustrated in FIG. 1. However, here the connection part 12 is of particularly compact design, and the relative position of the connection nozzles 16 and 34 is adapted to the geometrical conditions at the site of installation. The outer bodies 24 of the heat transfer part 14 are in both cases, however, not formed as tubes open at both ends with closures subsequently welded on, but rather have a single-part form. For connection, merely an individual weld seam 42 is therefore required toward the main body 40 of the connection part 12. FIG. 10 finally also illustrates an alternative sectional illustration of the connection part 12 of the temperature control element illustrated in FIG. 8.

FIGS. 11 to 13 illustrate alternative sectional views of a further temperature control device 10. This has a return flow duct 26 of particularly large volume and is suitable in particular for cooling casting cores. Here, too, the outer body 24 has a single-part construction without welding, and therefore no sealing problems arise. The connection part 12 has a particularly compact construction, and, in contrast to the other embodiments discussed to date, here the connections 16, 34 are not arranged in an end face 54 of the connection part 12, but rather on a lateral face 56. The main body 40 of the connection part 12 is connected to the outer body 24 of the transfer part 14 again by way of a weld seam 42.

As illustrated in FIG. 14, the inner body 20 of the heat transfer part 14 does not necessarily have to have a tubular form. In the exemplary embodiment illustrated, the inner body 20 has a bell-shaped end region 58, such that a narrow side duct 60 is formed at the end 22 of the duct 18, leading to a particularly high flow rate and therefore a particularly good dissipation of heat. If appropriate, the surface of the bell-shaped body 58 can also have structural elements which influence the flow in the ducts 18, 60, 26, in order, for example, to thus set laminarity or turbulence of the flow in order to influence heat transfer effects in a targeted manner. The bell-shaped body 58 can additionally also contain a heat store, for example in the form of an enclosed material having a high heat capacity, in order to thus achieve certain buffering of the transfer of heat in the heat transfer part 14. Sharp jumps in temperature which could lead to stress cracks can thereby be avoided.

FIG. 15 illustrates a plurality of temperature control devices 10 finally also in the context of a casting die denoted as a whole by 62. A temperature control device 10 as illustrated in FIG. 11 serves in this respect for core cooling in the core region 64 of the mold, which here serves for casting a thin-walled transmission housing 66. Two further temperature control devices 10 extend laterally into the mold plate 68 of the casting die 62, and serve for the actual cooling of the die. No further cooling ducts are required in the die 62, and this gives rise to a die which is particularly stable and low in stresses.

The openings 70 in which the cooling devices 10 are received are formed here as blind holes. For cooling regions close to the surface, however, provision can also be made of grooves, into which the temperature control devices 10 can be placed. Here, it is suitable to choose a rectangular cross-sectional shape for the temperature control devices 10. To improve the transfer of heat, a thermally conductive paste, for example a copper paste, can furthermore be introduced into the openings 70. 

1-10. (canceled)
 11. A temperature control device for a casting die, the temperature control device comprising: a connection section through which a temperature control medium flows, the connection part having an inlet and an outlet; and a heat transfer section operatively connected to the connection section and having a heat transfer body configured for insertion into a corresponding opening of the casting die and by way of which a heat exchange is carried out between the temperature control medium and the casting die to thereby control a temperature of the casting die.
 12. The temperature control device of claim 11, further comprising an inner body in the heat transfer body and, together with the heat transfer body forms a first flow duct for the temperature control medium.
 13. The temperature control device of claim 12, wherein the inner body comprises a heat storage element.
 14. The temperature control device of claim 12, wherein the first flow duct comprises a return flow duct for the temperature control medium.
 15. The temperature control device of claim 14, wherein the first flow duct extends over a predominant length region of the heat transfer body.
 16. The temperature control device of claim 11, further comprising an inner body in the heat transfer body, the inner body having a first flow duct.
 17. The temperature control device of claim 16, wherein the first flow duct comprises an inflow duct.
 18. The temperature control device of claim 16, wherein the first flow duct extends over a predominant length region of the heat transfer body.
 19. The temperature control device of claim 16, wherein the inner body comprises a heat storage element.
 20. The temperature control device of claim 12, wherein the connection section has a first connection nozzle in fluidic connection with the first flow duct.
 21. The temperature control device of claim 12, further comprising a second flow duct through which the temperature control medium flows back into the connection part.
 22. The temperature control device of claim 21, wherein the second flow duct is between the first flow duct and the heat transfer body.
 23. The temperature control device of claim 22, further comprising a bore in fluidic connection with the second flow duct and which permits a flow of the temperature control medium away from the second flow duct.
 24. The temperature control device of claim 11, wherein an outer surface of the heat transfer body has a flattened section configured to permit a flow of air displaced by insertion of the heat transfer body into the corresponding opening of the casting die out along the flattened section.
 25. The temperature control device of claim 11, wherein the heat transfer body has a first end region which is received by the connection part and heat-transferring region configured for insertion into the corresponding opening of the casting die.
 26. A casting die comprising: a casting die body having an opening configured to receive a heat transfer part of a temperature control device is inserted, wherein the temperature control device includes a connection section through which a temperature control medium flows, the connection part having an inlet and an outlet; and a heat transfer section having a heat transfer body configured for insertion into the opening of the casting die and by way of which a heat exchange is carried out between the temperature control medium and the casting die.
 27. The casting die of claim 26, wherein at least one outer surface region of the heat transfer body is in direct contact with a corresponding wall region of the casting die which delimits the opening.
 28. The casting die of claim 26, wherein a temperature of the casting die is controllable by the temperature control device.
 29. The casting die of claim 26, wherein the opening is arranged in a mold plate, a slide and/or a mold core of the casting die.
 30. A method for producing a die cast component, the method comprising: inserting a heat transfer section of a temperature control device into an opening of a casting die, the temperature control device having a connection section through which a temperature control medium flows, the connection part having an inlet and an outlet, the heat transfer section having a heat transfer body configured for insertion into the opening of the casting die; controlling the temperature of the casting die by way of a heat exchange between the temperature control medium and the casting die. 